Anti-freeze control mechanism



y 7, 1959 R. s. GRESKO 2,893,625

' ANTI-FREEZE CONTROL MECHANISM Filed April 7, 195a INVENTOR Ramon/0 5. GRESKO TQ NEY United States Patent ANTI-FREEZE CONTROL lVIECHANISM Raymond S. Gresko, Elyria, Ohio, assignor to Bendix- Westinghouse Automotive Air Brake Company, Elyria, Ohio, a corporation of Delaware Application April 7, 1958, Serial No. 726,963

8 Claims. (Cl. 230-202) This invention relates to control mechanisms and more particularly to mechanisms for controlling the supply of antifreeze medium to a fluid pressure system in order to prevent freezing of moisture trapped in the system.

One of the objects of the invention is to provide a control system for supplying anti-freeze to a fluid pressure system wherein the anti-freeze is supplied only when certain conditions prevail.

More specifically, it is an object of the present invention to provide a control mechanism for supplying antifreeze from a supply reservoir to a fluid pressure system which includes a compressor, a pressure reservoir and unloader means wherein the mechanism of the invention prevents the flow of anti-freeze to the system whenever the compressor is unloaded.

Another object of the invention is to provide a control mechanism of the foregoing type which is particularly suited for use with compressors having a supercharged inlet.

A still further object of the invention is to provide a control mechanism of the aforesaid type which includes compressible means for injecting a quantity of anti-freeze into the inlet of the compressor upon the latters becoming loaded and at the same time effects a fluid seal between the inlet and the anti-freeze reservoir so that any supercharging pressure at the compressor inlet is prevented from flowing into the anti-freeze reservoir.

Other objects and their attendant advantages will become apparent as the following detailed description is read in conjunction with the accompanying drawing which schematically illustrates one embodiment of the invention.

In the drawing there is illustrated a fluid compressor 10 which comprises the usual piston 12 operating in a cylinder 14 provided with the usual inlet and outlet ports 16, 18. The inlet port is controlled by a check valve normally urged by a spring 22 toward a seated position on an inlet seat 24 which serves to connect the inlet port 16 with an inlet chamber 26. The chamber 26 is desirably supercharged through a supercharging connection 28 connected to a conventional supercharging blower or the like (not shown) which may produce in the chamber a supercharged pressure on the order of, say, 10 to 12 p.s.i.

The outlet port 18 of the cylinder 14 is controlled by a conventionalcheck valve 30 urged toward a closed position by a spring 32 which permits the valve 30 to be unseated on the upstroke of piston 12 to admit compressed air to a conduit 34 which is connected to a conventional fluid pressure reservoir 36. The reservoir 36 has connected thereto a passage 38 leading to a fluid pressure governor 40 of conventional design having an outlet passage 4?. leading to an unloader cylinder 44 which contains an unloader piston 46, shown in the drawing in its up or unloading position but which is normally urged by a spring 48 towards its down or loading position indicated by the dotted line 50. The piston 46 has attached to its upper side a plunger 52 projecting into chamber 26 in axial alignment with inlet valve 20 so as to unseat the valve 20 when the reservoir pressure has risen to a predetermined high level causing the governor 40 to admit pressure to cylinder 44 to move piston 46 to the raised position of the drawing thereby permitting air to be passed back and forth around the opened check valve 20 so that no further pressure can be transmitted to the reservoir 36. The governor 40 is preferably of the snap acting variety which either admits or exhausts air from the unloader cylinder 44 with great rapidity when predetermined high or low pressures prevail in the reservoir 36 so that the inlet valve 20 is moved rapidly and fully between loaded and unloaded positions, the latter position being indicated by the dotted lines 20a.

The fluid pressure system described so far is essentially conventional. The present invention provides in combination with the described system an improved anti-freeze dispensing mechanism which includes an anti-freeze reservoir 54 adapted to hold an anti-freeze medium such as alcohol, the reservoir being connected by way of a conduit 56 to the upper end of a chamber or cavity 58 suit-ably formed in the wall of the inlet chamber 26. The reservoir 54 is preferably positioned with respect to chamber 58 so that the anti-freeze solution is fed continuously from the reservoir to the chamber by gravity and contained within the chamber is a piston 60 having a plurality of apertures 62 therethrough which enables anti-freeze to pass through the piston and onto a spongy compressible mass 64 which is preferably constructed of a porous heat-resistant material such as urethane foam or the like. An axial hole 66 extends through the mass 64 in alignment with a port 67 in the bottom of chamber 58 and extending through the hole and port is a stem 68 whose upper end is connected to the piston 60 and whose lower end is pivotally conected with the slotted outer end of a link 70 Whose inner end is pivotally fixed at 72 to the wall of the inlet chamber 26 as shown. The stem 68 is preferably of less diameter than the hole 66 and integral therewith is a valve 74 which is adapted to open or close the port 67 as the stem 68 is moved upwardly or downwardly by the link 70 which is connected by a conventional slot and pin arrangement 76 to the unloader plunger 52 so as to be swung about its fixed pivot 72 as the plunger is moved between its loading and unloading positions.

In operation, with initially no air pressure existing in Zthe system but with the reservoir 54 supplied with antifreeze solution, the unloading piston 46 will be in its down or loading position, the anti-freeze supply valve 74 will be open and the piston 60 will occupy substantially the position indicated by the dotted lines 60a so that the porous material 64 is compressed into a compact mass producing bulges, indicated by the dotted lines 64a, which closely engage stem 68. When the compressor 10 is started and supercharged pressure is admitted at connection 28 to inlet chamber 26, air is pumped by piston 12 into reservoir 36 until the pressure is equal to the governor setting at which point unloading pressure is rapidly admitted to cylinder 44 causing piston 46 to move to its full-line position unseating inlet check valve 20 so that the compressor is unloaded. As the unloading plunger 52 moves upwardly it swings lever 70 counterclockwise in the drawing until valve 74 closes port 67 at which point the piston 60 assumes the full-line position shown, thereby permitting spongy mass 64 to expand so that anti-freeze solution on top of piston 60 is drawn through the apertures 62 to saturate the mass 64. When the pressure in reservoir 36 falls to the low pressure setting of governor 40, this rapidly exhausts fluid pressure from cylinder 44 permitting piston 46 to return to its dotted line position 50 under the influence of return spring 48. As plunger 52 moves downwardly, lever 70 is swung clockwise to its dotted line position 70a caus ring valve 74 to open port 67 thus moving piston 60 downwardly to compress mass 64 and squeeze therefrom anti-freeze solution absorbed therein which then enters the inlet chamber 26 and is'entrained in the air flowing into the inlet of cylinder 14 from whichthe anti-freeze is ejected through the-outlet 18into the reservoir 36 with the compressed air. Since in its compressed state, the mass 64- bulges around stem 68 as indicated at 64a, this bulge in combination with the compressed state of mass 64 effects a substantially fluid-tight seal between piston 60 and the port 67, thus preventing on the one hand, uncontrolled flow of anti-freeze solution into inlet chamber 26 and, on the other hand, preventing the escape of supercharging pressure up through the chamber 58 into the anti-freeze reservoir 54. i

Since plunger 52 moves downwardly under the action of spring 48 with'substantially a snap action (limited only by the resiliency of mass 64), the great majority of the anti-freeze solution in the mass will be injected into the inlet 26 though naturally some will flow upwardly through the apertures 62 in the piston 60. By controlling the number and size of the apertures 62, thequantity of liquid flowing in the reverse direction can be limited to a 'very small amount so that substantially all of the antifreeze solution in the mass 64 enters the inlet chamber '26. Should some supercharging pressure seep by the seal formed by the compressed mass, it will be apparent that this will be only a very slight amount which can be amply'taken care of through the usual vent in the reservoir 54. 4

Though the anti-freeze injecting unit of the invention is particularly adapted for 'use with compressors having a supercharged inlet since it injects anti-freeze into the inlet while preventing by-passing of the supercharging pressure through the anti-freeze supply means, it will be apparent to those skilled in the art that the invention will serve non-supercharged compressors as well, in which event the connection 28 would merely be joined with a conventional air strainer. Regardless of which type of compressor is employed, the invention provides elfective means for injecting into the inlet a controlled amount of anti-freeze with the injection taking place only when the compressor is loaded and actually delivering compressed air to the pressure reservoir. Thus the present invention eliminates danger of rapid and unknown depletion of the anti-freeze reservoir which frequently occurs in other systems in which anti-freeze is supplied to the inlet regardless of the loaded condition of the compressor.

It will be apparent that the invention is susceptible of various modifications and changes without, however, departing from the scope and spirit of the appended claims.

What is claimed is:

1. Mechanism for supplying anti-freeze to a fluid pressure supply system of the type provided with a reservoir, a compressor having an inlet and an outlet connected to said reservoir, andunloading means including an actuator movable between loading and unloading positions in response to predetermined pressures in said reservoir, an anti-freeze dispensing cavity having a port conhecting said cavity to said inlet, an anti-freeze supply container having a fluid connection with said cavity for continuously supplying the same with antifreeze, compressible sponge-like material in said cavity adapted to absorb anti-freeze when in expanded condition, means in said cavity for compressing said sponge-like material comprising a piston-like member overlying said sponge-like material, a valve movable between opened and closed positions'for controlling said port, means connecting said piston-like member and said valve so that upon movement of the latter to open position the former bears on said sponge-like material to compress the same and eject absorbed anti-freeze through said port to said inlet, and an operative connection between said valve and said actuator to effect opening of said valve when said actuator is moved to loading position andto eflect closing of said valve when said actuator is moved to unloading position.

2. Mechanism for supplying anti-freeze to the inlet of a compressor provided with an unloader having an actuator movable between loading" and unloading positions, an anti-freeze dispensing cavity having a port connecting said cavity with said inlet, means for continuously supplying anti-freeze to said cavity, compressible sponge-like material in said cavity adapted to absorb anti-freeze when in an expandedcondition, a piston-like member in said cavity movable towards or away from said sponge-like material to compriess the same or permit its expansion depending on the direction of movement of said piston, a valve movable between open or closed positions to control said port, means connecting said valve and said piston so that movement of the former to closed position causes {said piston to be moved away from said compressible material and vice versa, and an operative connection be- !tween said actuator and said valve to effect closing of said valve when said actuator is moved to loading position and to effect closing of said valve when said actuator is moved to unloading position.

3. Mechanism for supplying anti-freeze to the inlet of a compressor having an inlet and an outlet connected to a reservoir, an anti-freeze dispensing cavity continuously supplied with anti-freeze and having a port connected to said inlet, compressible sponge-like material in said cavity, a piston overlying said material and movable towards or away from said material to compress the same or permit the expansion thereof depending on the direction of movement of said piston, a valve movable. between open or closed positions to control said port, means connecting said valve and said piston so that movement of the former to open position moves said piston towards said compressible material to squeeze anti freeze therefrom for entry into said compressor inlet through said port and movement of the said valve tov closed position moves said piston away from said material to permit expansion thereof and absorption of anti-freeze thereinto, and pressure responsive means for moving said valvebetween open and closed positions in response to predetermined pressures in said reservoir.

4. Mechanism of claim 3 in which the connecting means between said valve and piston comprises a rodlike member extending through said port, said compressible material in compressed condition being adapted to closely encompass said rod to form a fluid-tight seal for preventing the uncontrolled passage of anti-freeze through said port.

5. Mechanism of claim 3 in which the pressure responsive means for controlling the valve comprises an unloader including an actuator movablebetween loading and unloading positions in response to predetermined pressures in said reservoir and an operative connection between said actuator and said valve to effect opening thereof only when said actuator is moved to loading position and to effect closing of said valve when said actuator is moved to unloading position.

6.'Mechanism in accordance with claim 3 wherein said piston is provided with restriction orifices permitting the passage of anti-freeze through said piston to said compressible material when said piston is moved in a direction away from said material, the orifices restricting the reverse flow of anti-freeze through said piston when it is moved-in a direction to compress said material.

7. In combination, a fluid pressure supply system of the type having a reservoir, an air compressor having a discharge connection connected to the reservoir, an inlet connection connected to a source of supercharging air pressure greater than atmospheric, an unloader having an actuator movable between loading and unloading positions in response to predetermined pressures in said reservoir, and anti-freeze supply mechanism for supplying anti-freeze totheinlet connection comprising an'anti-free'ze dispensing cavity having a port connected to said inletcon'n'ection, an anti-freeze supply. container for continuously supplying said cavity with anti-freeze, compressible spongy material in said cavity having one side adjacent said port, said material being adapted to absorb anti-freeze when in expanded condition and to eject the absorbed anti-freeze through said port when said material is compressed, a piston in said cavity overlying the side of said compressible material opposite said port, a valve movable between open and closed positions for controlling said port, a rod-like member extending through said port and said compressible material to connect said piston to said valve so that when said valve is moved to open position said piston is moved against said material to compress the same, said material being adapted when compressed to form a fluid seal around said rod and between said port and cavity to prevent the uncontrolled flow of anti-freeze in one direction and the flow of supercharged air in the opposite direction between said inlet and said cavity, and means operatively connecting said valve to the actuator of said unloader so as to open said valve only when said actuator is in loading position and to close said valve when said actuator is in unloading condition.

8. Mechanism for supplying anti-freeze to a compressor having a supercharged inlet comprising an antifreeze dispensing cavity continuously supplied with antifreeze and a port connecting said cavity to said inlet, compressible spongy material in said cavity overlying said port, a piston-like member overlying said material on the side thereof opposite to the side overlying said port, a valve movable between open and closed positions to control said port, and a rod extending through said port and said spongy material to connect said valve and said piston-like member so that movement of the former to open position causes said piston member to compress said spongy material, said material when compressed being adapted to form a fluid seal around said rod and between said port and cavity to prevent uncontrolled fiow of anti-freeze in one direction and the flow of supercharged air in the opposite direction between said inlet and said cavity.

No references cited. 

